If that is a lottery, perhaps I will follow my instinct because no matter what I use, it will rely on luck. Betting on the same set of numbers or changing up the set will not be a problem for me so that will not increase my chance to win.
But the thing that I always remember is how to prevent spending more money buying a lottery. That will not guarantee a win because that will be back on my luck. I prefer to use the same amount of money to buy the ticket.